Thermodynamic Investigation of NaClO₃ Solubility in the Mixed Solvent Medium and the Related Ion – Pair Formation at Different Temperatures
Pages 173-177
Mehran Aghaie and Roshanak Kishani

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.04.2

Published: 17 December 2015

Abstract: Using the evaporating method, the solubility of sodium chlorate was determined in the various mixed solvents (water + ethanol + propanol) at various temperatures. The results showed that the solubility of NaClO₃ decreases with increasing the mass percent of ethanol and propanol. On the other hand, the solubility of NaClO₃ increases with increasing the temperature .In addition, the equilibrium constant of ion pair formation, K_IP, for the reaction

Na⁺_(aq) + ClO₃^-_(aq) Na⁺ClO₃^- _{(Ion Pair)} was estimated upon Fuoss contact ion pair model and then, the values of ion-pair concentrations were determined by using the extended Debye-Hückel model and iteration calculations in various mixed solvents and various temperatures . Finally the value of thermodynamic solubility product constant, K_sp(th), and the values ΔH°, ΔS° and ΔG° of and of ion-pair formation were estimated in the mixed solvent media.